TWI460959B - Charging system of battery module and charging method thereof - Google Patents

Description

Battery module charging system and charging method thereof

The invention relates to a charging method, in particular to a voltage control structure for a battery and maintaining a certain voltage charge.

According to the advancement of technology, the use of portable products has increased, so lithium batteries have become popular as secondary batteries for portable computers, mobile phones, and the like.

In the case of a battery used in a general portable computer, the battery is composed of a plurality of batteries and connected in series to form a battery module. The battery module formed by the plurality of batteries has sufficient power supply. Most of the batteries used in current portable computers are lithium batteries. The lithium battery has a characteristic that the terminal voltage is slightly decreased when the battery is fully charged. Therefore, the lithium battery is charged with a constant voltage and current, and the voltage and current are measured. The temporal change is used as a method of charging such batteries as a method of determining whether or not the battery is fully charged and ending charging after being fully charged.

However, a common charging method is to perform charging with a constant voltage and current, and measure the terminal voltage. After the single-terminal voltage reaches a certain voltage value, intermittent charging is performed intermittently, and the intermittent charging is repeated for a certain period of time until charging. After that, the charging is interrupted, and the terminal voltage is lowered to a fixed value, and it is checked whether the reduced stable voltage is equal to or higher than the standard value. If it is determined to be equal to or greater than the standard value, it is determined that the battery is fully charged.

In the above charging methods, the interruption time during the intermittent charging is long because the charging is interrupted until the terminal voltage is stabilized, so that the charging method still has a drawback that the charging time is long.

In order to improve the shortcomings of the charging method described above, in the case of the Republic of China Patent Gazette, the public number is 200830608, which is an improvement on the charging method, wherein the case mentions a voltage-controlled charging method by reducing charging Voltage level, and judge whether the cell voltage reaches the rated voltage. Once the rated voltage is reached, reduce the charging voltage by one level, and finally judge whether the battery power is full. If it is full, stop charging the battery; if not When fully charged, the above-mentioned lowering of the charging voltage level is repeated, and the cell voltage step is judged until the battery is fully charged.

In view of the above-mentioned charging problem, the purpose is to achieve a fast and safe charging of the secondary battery in a short period of time, and is different from the charging method described in the above publication.

The main object of the present invention is to provide a charging system with a charging voltage higher than the charging cut-off voltage, wherein the charging state is controlled by the charging switch, and when the charging determination period continues to be greater than or equal to the charging determination voltage, the charging is achieved. Saturated conditions, therefore can effectively reduce the charging time, and can indeed prevent battery overcharge, in order to maintain battery life and normal charge and discharge capacity.

In order to achieve the above object, the charging method of the present invention is a charging method of a battery module, and the charging method includes a step 1 of setting a charging voltage higher than a charging cutoff voltage as a system charging to provide a larger charging current; Detecting whether the battery voltage is greater than the charge cut-off voltage; Step 3: When the battery voltage is greater than the charge cut-off voltage, suspend charging and confirm whether the charging voltage is greater than the minimum charging voltage. If the charging voltage is less than or equal to the minimum charging voltage, the voltage is no longer adjusted. Charging voltage; Step 4: If the battery open circuit voltage reaches the fullness determination voltage and continues to fill the determination time, it is determined that the battery is full and stops charging; Step 5: If the fullness determination voltage is not reached, the charging voltage is lowered and restored Charging until the battery open circuit voltage reaches the full charge determination voltage and continues to fill the determination time.

Therefore, according to the charging method of the present invention, by using the voltage control, a large charging voltage mode is provided at the initial stage of charging, and when the charging voltage reaches the charging cut-off voltage, the charging state is controlled by the charging switch, so that the battery can be surely prevented. Overcharge, and by delay time is used as a way to determine whether the battery voltage is greater than the full-charge determination voltage during this time, to accurately determine whether the battery is fully charged, and to continue to overwrite the read-fill condition, thereby maintaining battery life and Normal charge and discharge capacity.

It can be seen that the charging mode of the present invention adopts voltage control, and provides a large charging voltage mode at the initial stage of charging, and when the charging voltage reaches the charging cut-off voltage, the charging state is controlled by the charging switch, and the delay time is Whether the battery voltage is greater than the fullness determination voltage during this time to accurately determine whether the battery is fully charged or not; compared with the use of the above disclosure, the charging voltage level is lowered, and the voltage of the battery is judged to be rated. After the voltage reaches the rated voltage, the charging voltage is lowered by one level, and finally the method of judging whether the battery power is full or not is used. Although both methods use the voltage charging method as the determination condition for the battery to be full, the present invention is a new research and development technology. The actual charging process and control method are different from the methods disclosed in the case.

The drawings of the specific embodiments of the present invention are described in detail as follows: Referring to the first and fifth figures, the battery module charging system of the present invention comprises a battery module 1 and a charging system 2. The battery management unit 3 and the charging switch 4 are configured. The battery module 1 includes one or more batteries 11 , and the battery module 1 is supplied with charging power by the charging system 2 . The charging system 2 provides charging voltage and current for supplying. The battery module 1 is charged, and a large charging voltage is provided at the initial stage of charging. The battery management unit 3 controls the charging state and determines whether the battery is fully charged or not, and controls the charging suspension, shutdown or opening by the charging switch 4. .

Referring to the first to fifth figures, the charging method of the present invention is for charging the battery module 1 composed of at least one battery cell 11. The battery system in this embodiment includes six The battery cell 11 (three battery cells are connected in series and two battery cells are connected in parallel) is configured. The charging voltage of the present invention is charged by externally, thereby charging the battery module 1 to be charged.

The charging system charges the battery module with a large charging voltage 10 (step S10), and detects whether the battery voltage 30 is greater than or equal to the charging cut-off voltage B (step S20). At this time, if the battery voltage 30 is greater than or equal to the charging cut-off voltage B Then, the charging of the battery is suspended (the pause, the closing or the opening of the charging is controlled by the charging switch) (step S30), and the charging current 20 is turned off when the charging is suspended and the battery voltage 30 is decreased, during the off setting time of the charging suspension. The battery voltage 30 drops. At this time, it is judged whether the charging voltage 10 is greater than the minimum charging voltage E (step S40). If the charging voltage 10 is greater than the minimum charging voltage E, the charging voltage 10 is lowered (step S50). After the required charging voltage 10 is lowered, the step S60 is performed. The delay time is used as the charging system reaction time to obtain the correct charging voltage 10; when the battery voltage 30 decreases with the charging suspension, the delay time is also used as the reading battery voltage 30 during this time is greater than or equal to the fullness determination voltage. C (step S70), the duration T of S80 is defined based ₁ 30 determines that the battery voltage is determined to be greater than the fully charged voltage C; T ₁ is greater than when the duration of full charge When the time T ₂ is determined, it is determined that the battery is full (step S90).

In the above step S20, if the battery voltage 20 is smaller than the charge cutoff voltage B, it is recharged.

According to the above-mentioned shutdown setting time of the charging suspension, it is judged whether the adjusted charging voltage 10 is greater than the minimum charging voltage E (step S40), and if the charging voltage 10 is less than the minimum charging voltage E, the charging voltage 10 is not adjusted and recharged. .

In step S70, when the battery voltage 30 decreases with the charging suspension, it is determined whether the battery voltage 30 is greater than or equal to the fullness determination voltage C during the delay time. If the fullness determination voltage C is less than the battery voltage 30, the process returns to step S10 to recharge. .

The determination of the S80 battery fullness must be that the duration T _{1 is} greater than or equal to the fullness determination time T ₂ , and the battery voltage 30 waits for the duration T ₁ , and if the battery voltage 30 is less than the fullness determination time T ₂ , then the determination is made. The battery is not fully charged and the charging step must be repeated until the battery's power is fully read.

In this embodiment, at the beginning of charging the battery, a charging voltage higher than the charging cutoff voltage is provided as system charging to provide a larger charging current, so that the charging time of the present invention is shortened, and the battery voltage 30 is used to reach the charging cutoff. When the voltage B is controlled by a charging switch, the charging is suspended and the current is turned off. At this time, the charging voltage is lowered, and if the battery voltage continues to be higher than the fulling determination voltage during the charging time, the charging is fully charged.

In summary, the charging method of the battery module of the present invention can effectively reduce the charging time, and the charging suspension control of the charging switch can be used to implement the charging voltage determination, thereby preventing the battery from being overcharged, thereby maintaining the battery life and normal charging and discharging. capacity. However, the present invention has an improvement in efficiency compared with the conventional charging method, and the technical means and its construction are indeed developed by the inventor of the present invention. The invention of the present invention is in accordance with the requirements of the invention patent, and the applicant is proposed according to law. Application. The above description is only the preferred embodiment of the present invention, and equivalent modifications or variations of those skilled in the art of the present invention are intended to be included in the following claims.

10. . . Charging voltage

20. . . recharging current

30. . . battery voltage

1. . . Battery module

11. . . Batteries

2. . . Battery management unit

3. . . Charging system

4. . . Charging switch

A. . . Final charging voltage

B. . . Charge cutoff voltage

C. . . Fully determined voltage

D. . . Battery full

E. . . Minimum charging voltage

T ₁ . . . duration

T ₂ . . . Fullness determination time

S10～S90. . . The steps of the battery charging method of the present invention

The first figure shows a flow chart of the charging circuit of the present invention.

The second figure shows a graph of the charging voltage and the state of charge of the battery cell of the present invention.

The third figure shows a graph of the charging current and charging voltage of the present invention.

The fourth graph shows a time display graph of the fullness determination of the present invention.

The fifth figure shows a block diagram of a charging system of the battery module of the present invention.

S10～S90. . . The steps of the battery charging method of the present invention

Claims (5)

A charging method for a battery module, the charging method comprises the following steps: Step 1: setting a charging voltage higher than a charging cutoff voltage as a system charging to provide a larger charging current; and step 2, detecting whether the battery voltage is greater than a charging cutoff voltage Step 3: When the battery voltage is greater than the charge cut-off voltage, suspend charging until the battery voltage reaches the final charging voltage; Step 4: If the battery voltage reaches the charge cut-off voltage, stop charging, after stopping charging, turn off the battery voltage, wait for The time is a set delay time. After the charging switch is turned on again, the battery voltage is judged to be greater than the fullness determination voltage. If the charging cut-off voltage is not reached, the charging voltage is lowered and the charging is resumed until the charging cut-off voltage is reached. The charging method of the battery module according to claim 1, wherein the charging cutoff voltage is between a battery specification maximum allowable charging voltage and a set fullness determining voltage. The charging method of the battery module according to claim 1, wherein the final charging voltage is a maximum charging voltage that the battery is allowed to charge. The method for charging a battery module according to claim 1, wherein the method for determining whether the battery module is full is: whether the battery charging voltage is greater than or equal to the set fullness determination voltage; The determination voltage determines that the battery is not full; if it is greater than the full determination voltage, it is determined that the battery is fully charged. The charging method of the battery module according to claim 1, wherein the battery voltage charging suspension and recharging are controlled by the charging switch, and the voltage is controlled when the voltage exceeds the maximum charging voltage.